Place one light in the scene and turn it off if you do not like to use any additional lights with IBL. Bypassing this procedure will lead to the installation of default lights even if you answered NO in the warning message. \r\n
TurboCAD tutorial explains how to accurately aim a directional light to represent the sun at a particular time of day and a particular time of the year, Winston Mitchell, Winston`s TurboCAD Pages, August 24, 2003 \r\n